Filing cabinet

ABSTRACT

A filing cabinet containing a plurality of independently operable sliding compartments, each having its own door, in which all of the unopened doors in the cabinet are locked and prevented from opening in response to the opening of any one of the doors of the cabinet. The cabinet contains a pair of vertically slidable locking bars, which span the various compartments. Each locking bar has a plurality of notches through which move various fall supports supporting each of the doors in its open horizontal position. Each of the fall supports has a first camming surface on it which momentarily cams the locking bars upwardly when a door is moved to its open position. At the same time that a door is moved into open position, a combined friction catch-interlock moves to a position underlying its respective fall support and within its respective notch, the effect being to prevent the locking bars from being moved upwardly. When any of the remaining doors is to be opened, the cams contact the locking bars and, being unable to move them upwardly, in effect prevent the door from opening; i.e., the cams cannot pass the locking bars. Upon closure of the opened door, each friction catch-interlock is cammed from its underlying position beneath a fall support, thereby again permitting the locking bars to be moved in an upward vertical position through the space formerly occupied by the friction catch-interlocks. The invention also encompasses a single locking unit by which all of the doors can be maintained in a locked position. The door containing the locking unit can be at any level to accommodate easy access. The locking unit includes a lock arm, which is received within a notch in each locking bar such that when the lock is closed, the locking arm maintains the locking bars in their downward cam locking position. When the lock is opened, the lock arm is moved to a second position such that the locking bars can be vertically raised.

United States Patent Otto D. Lewin 210 Elmwood Boulevard, York, Pa.17402 [21 1 Appl. No. 56,796

[22] Filed July 21, 1970 [45] Patented Aug. 31, 1971 [72] Inventor [54]FILING CABINET 10 Claims, 13 Drawing Figs.

[52] 11.8. CI 312/220, 312/222, 312/219 [51 1 Int. Cl A47b 88/16 [50]Field of Search... 312/320,

Primary Examiner-James T. McCall Attorney-Sidney N. Rosenfeld ABSTRACT:A filing cabinet containing a plurality of independently operablesliding compartments, each having its own door, in which all of theunopened doors in the cabinet are locked and prevented from opening inresponse to the opening of any one of the doors of the cabinet. Thecabinet contains a pair of vertically slidable locking bars, which spanthe various compartments. Each locking bar has a plurality of notchesthrough which move various fall supports supporting each of the doors inits open horizontal position. Each of the fall supports has a firstcamming surface on it which momentarily cams the locking bars upwardlywhen a door is moved to its open position. At the same time that a dooris moved into open position, a combined friction catch-interlock movesto a position underlying its respective fall support and within itsrespective notch, the effect being to prevent the locking bars frombeing moved upwardly. When any of the remaining doors is to be opened,the cams contact the locking bars and, being unable to move themupwardly, in effect prevent the door from opening; i.e., the cams cannotpass the locking bars. Upon closure of the opened door, each frictioncatch-interlock is cammed from its underlying position beneath a fallsupport, thereby again permitting the locking bars to be moved in anupward vertical position through the space formerly occupied by thefriction catch-interlocks. The invention also encompasses a singlelocking unit by which all of the doors can be maintained in a lockedposition. The door containing the locking unit can be at any level toaccommodate easy access. The locking unit includes a lock arm, which isreceived within a notch in each locking bar such that when the lock isclosed, the locking arm maintains the locking bars in their downward camlocking position. When the lock is opened, the lock arm is moved to asecond position such that the locking bars can be vertically raised.

PATE NTED was! l9?! INVENTOR. OTTO Ewm sum 1 0r 4 PATENIED AUBBI I971 3,602.564

' sum 2 UF' '4 INVENTOR. OTTO D. LEWIN PATENTEUAUGBI 19?: 35025 4 sum 3OF 4 INVENTOR.

OTTO D. LEWIN PATENTEB Aussl I97! 3,602,564

xum u [If 4 INVENTOR. ll OTTO o. LEWIN FIG. [0 BY FILING CABINETBACKGROUND OF THE INVENTION The invention relates to the interlocking ofall the remaining doors ofa filing cabinet when one of the doors isopened, thereby preventing the opening of more than one door at a time.

It has long been the practice to provide filing cabinets with somemechanism for preventing the opening of more than one door or drawer ata time. This is to prevent the accidental toppling or tipping of thecabinet when more than one door is opened, with the consequentpossibility of injury, and also the disruption of the papers containedin the cabinet. This problem of tipping is particularly acute in themodern file cabinet, which is generally of considerable vertical height.It will be apparent that the opening of more than one of the uppermostdoors or drawers could quite easily result in the tipping of the entireunit. I

There have been many techniques devised to prevent the opening of morethan one door; one such technique is to provide each door with its ownlocking mechanism. This suffers from two defects. One being the expense,and the second being the possibility of two doors being inadvertently orotherwise unlocked, thereby permitting the opening of two doors at thesame time. Desirably, the unit should be so constructed that this is notpossible.

Other techniques have been devised which accomplish the desired purposebut which, however, are often expensive,

quite cumbersome in operation with various protruding parts,

pins, notches, adding to the complexity of the design and cost. Further,many of such designs do not have a positive lock, which oftentimes couldpermit a second door to be opened when the unit is jarred.

Accordingly, it is an object of this invention to provide a filingcabinet of the type having a selected number of slidable compartments,each maintained within the cabinetby its own individual door and inwhich the opening of one door has the positive effect of locking allother doors until such time as the one opened door is closed.

A further related object is to achieve the locking of the doors of thefiling cabinet of the type just above mentioned by an arrangement,-simple in design and which acts to lock the doors in a positive fashion.A still further object is to achieve the desired effect by anarrangement, which is simple in design and of low cost.

A still further object is to provide, in a filing cabinet of the typeabove mentioned, means for locking all the doors of the cabinet by asingle locking mechanism.

SUMMARY OF THE INVENTION In accomplishing the objects of the invention,there is provided a filing cabinet, containing a plurality of slidingcompartments, each compartment being maintained in its closed positionby a hingedly mounted door. The dooropens to a horizontal position andis maintained in its horizontal position by the cooperation between thefiling cabinet compartment and two fall supports, one on either side ofeach door. When the door is opened to its horizontal position, it formsa base for receiving an opened compartment. A pair of slidable lockingbars are provided having a plurality of notches therein, each of thenotches adapted to receive one of the fall supports for each door. Theaction of the two locking bars is identical, therefore, to facilitateunderstanding, the invention will be described with reference to onelocking bar and its fall supports. Each of the fall supports contains afirst camming surface. which is adapted in its opening position to camits locking bar momentarily upward. It can be appreciated that, in theevent a bar is prevented from upward movement, it acts as a lockingmechanism preventing the passage of the fall support, maintaining thedoor in its closed position. To accomplish this, there are provided aplurality of combined friction catch-interlocks, one each positionedadjacent each of the fall supports. The interlocks are spring mountedwith the spring force being such that, when a door is moved to its openposition, the spring forces the friction catch-interlock underneath thefall support and within the respective notch. In this position, theentire space within the notch is filled and the locking bar cannot beraised, having the effect, as aforesaid, of maintaining the other doorsclosed. Each fall support has a second camming surface, which cams thefriction catch-interlock out from beneath the fall support when the dooris returned to its closed position, thereby permitting the locking barto be vertically raised.

In addition, a single locking mechanism is provided for maintaining allof the doors of the cabinet locked. This is accomplished by way of alocking mechanism having a lockarm received within a lock arm notch ineach vertical locking bar. The effect is such that when the lockingmechanism is in its locked position, the lock arm prevents the verticallocking bars from being raised; in its unlocked position, the verticallocking bars are permitted to be raised by the camming surface on anyone of the fall supports.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of thefile cabinet with a portion broken away to show the interior.

FIG. 2 is an isometric view of the file cabinet with one compartmentextended and the compartment door in its opened compartment supportingposition.

FIG. 3 is a partially broken view in side elevation showing acompartment door in closed position.

FIG. 4 is a partial vertical elevation of a slidable locking bar-withinterconnecting means shown to larger scale than FIG. 3.

FIG. 5 is a partial vertical section to same scale as FIG. 3- showingslidable locking bar and spring loading.

FIGS. 6, 7 and 8 are vertical sections to scale of FIG. 4- showing theslidable locking bar in various operative positions.

FIG. 9 is a partial horizontal section taken on the line 9-9 of FIG. 3.

FIG. 10 is a partial front elevation of the main locking mechanism.

FIG. 11 is a section taken on the line 11-11 ofFIG. 10.

FIG. 12 is a partial vertical section showing the locking arm interlock.I

FIG. 13 is a partial view in forward elevation of the locking bar.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE DRAWINGS FIG. I shows afile cabinet 10 of the type containing a plurality of slidingcompartments 1 I, each compartment 11 being maintained in its closedposition by an individual door 12. File cabinet 10 may be of the unitarycasing-type or may be assembled from a plurality of individual singlecompartment units. Door 12 is of the type which rotates from a closedvertical position to a horizontal open position. Each door 12 isattached to the cabinet by a pair of hinges 13 attached to the sidewallsof the cabinet 10 by a bolt 13a. Hinge 13 comprises a hinge mounting 13breceiving the arm (not shown) of a pivot 13c, all as is typical in theart. Door 12 is maintained in its open position by a pair of fallsupports 14, only one of each pair being shown. I

File cabinet 10 is provided with a pair of slidable locking bars 15,spanning the compartments l1 and extending the full height of the filecabinet, only one such locking bar being shown. While for conveniencehereinafter we refer to but one locking bar and its fall supports, itwill be appreciated that the action of both locking bars is identical.

Locking bar 15 is slidably mounted on the side panel of the unit forvertical movement by any conventional means. Locking bar 15 contains aplurality of two-step notches 16 therein, comprising an inner notch 16aand an outer notch 16b, each inner notch 16a being adapted to receiveone of the fall supports 14 for each door 12. Since the actionof thenotches and the associated fall supports are identical, only one setwill be described. Fall support 14 has a first camming surface l7thereon for momentarily camming locking bar 15 vertically upward.Adjacent each fall support 14 is a combined friction catch-interlock 18,which is positioned within outer notch 16b and attached to a side panelof cabinet by a bracket 19. Fall support 14 has a second camming surface20 thereon, which, in the closed position of door 12, maintains frictioncatch-interlock 18 in its FIG. 6 position. Friction catch-interlock 18is spring biased to its locking position underlying a fall support 14,as shown particularly in FIG. 8.

To maintain locking bars in a downward position, a pair of leaf springs21 are provided within a top cover 22 of cabinet 10, each resting on alock bar connector 23 received within a bracket 24 at the verticallyuppermost position of locking bar 15. Leaf spring 21 acts tocontinuously bias locking bar 15 to its downward position by thepressure on lock bar connector 23. Lock bar connector 23 serves a secondpurpose, which is to permit the addition of compartments to filingcabinet 10.

Each compartment contains its own individual locking bars 15 completewith a locking bracket 24. To add a compartment, it is merely necessaryto remove top cover 22 and place a new compartment on top of theassembled unit. The lock bar connector 23 of the unit in place will bereceived within the corresponding bracket 24 of the new unit beingadded, locking the assemblage into a completed whole. Top cover 22 isreplaced and the assemblage is completed.

A locking mechanism 25 is provided for locking all of the doors [2 intheir closed vertical position. Locking mechanism 25 comprises a lock 26inserted within an opening 27 in any one selected door 12. The door 12selected will be at the conveni'ence of the purchaser to place thelocking mechanism 25 at whatever height is desired. Lock 26 extendswithin opening 27 and terminates in a lockpin 28. Lock 26 is attached toa lock arm 29 by way of a spring loaded hinge 30. Lock arm 29 has a pairof lock arm ears 3], which are received within a notch 32 in eachlocking bar 15. When lock 26 is in its locked position, as seen in fulllines in FIG. 11, lock arm ears 31 are received within notches 32, as isshown particularly in full lines in FIG. 12, preventing upward movementof locking bar 15. To open lock 26, lock pin 28 is rotated so that itmay pass through opening 27. When this occurs, spring loaded hinge 30forces the lock 26 to its open position, as shown in dotted lines inFIG. 11. This, in effect, rotates lock arm 29, see FIGS. 11 and 12,thereby also effectively rotating lock arm cars 31 to their dotted lineFIG. 12 position, permitting locking bars 15 to be moved verticallyupward. The hinged motion of lock arm 29 makes for great simplicity ofoperation and is relatively inexpensive.

OPERATION In operation, for any one of the doors 12 to be opened, it isnecessary for its particular camming surface 17 to be rotated pastlocking bar 15. So long as locking bar 15 is permitted to move upward,any camming surface 17 will cam it upwardly and immediately thereafterlocking bar 15 will be biased to its downward vertical position by leafspring 21. Assume a door 12 is opened and camming surface 17 camslocking bar 15 momentarily upwardly (see FIG. 6). After camming surface17 has passed from beneath its respective notch 16, locking bar 15 againassumes its downwardly biased position (see FIG. 7). A moment later,camming surface passes from adjacent friction catch-interlock l8 andfriction catch-interlock I8 is spring biased to a position underlyingfall support 14 (see FIG. 8). As will be seen from an inspection of thislatter figure, when friction catch-interlock I8 underlies a fall support14, the combined width of the two effectively fills inner notch 16a withthe bottom of friction catch-interlock 18 resting on the bottom of innernotch 16a preventing locking bar 15 from being raised upwardly. In thisposition, when someone attempts to open a second door 12, it will beapparent that camming surface 17 on the respective fall support 14 willcontact locking bar 15. Unable to raise locking bar 15, camming surface17 then acts to prevent the passage of fall support 14 through the notch16 maintaining door 12 in its closed position. When the open door 12 isclosed, second camming surface 20 acts to force friction catch-interlock18 to its outward disengaged position, as shown in FIG. 6. When this isaccomplished, locking bar 15 is again able to be vertically raised,thereby permitting the opening of another door 12 by allowing aparticular camming surface 17 to cam locking bar 15 upwardly.

I wish it to be understood that my .invention is not to be limited tothe specific constructions and arrangements shown and described, exceptonly insofar as the claims may be so limited, as it will be apparent tothose skilled in the art that changes may be made without departing fromthe principles of the invention.

What is claimed is:

1. In a filing cabinet containing a set of slidable compartments,apparatus for maintaining the remaining compartments of said cabinet ina closed position when a selected one of said compartments is openedcomprising a slidable locking bar spanning said compartments, means formomentarily camming said locking bar vertically to an upper positionwhen any one of said compartments is opened, and means for locking saidslidable locking bar when it has reached its lower position after beingmomentarily cammed upwardly by any one of said compartments being openedthereby preventing opening of a second compartment.

2. The filing cabinet as set out in claim 1, and further including alocking mechanism for maintaining said slidable locking bar immovablewhen said locking mechanism is in a locked position, and permittingmovement of said slidable locking bar when said locking mechanism is inan unlocked position.

3. In a filing cabinet containing a set of slidable compartments,apparatus for maintaining the remaining compartments of said cabinet ina closed position when a selected one of said compartments is openedcomprising a slidable locking bar spanning said compartments, means forvertically raising said locking bar to an upper position when any one ofsaid compartments is opened, means cooperating with each of saidcompartments permitting opening of a compartment when said'slidablelocking bar is in its vertically raised position, and means for lockingsaid slidable locking bar in a lower position when any one of saidcompartments is opened thereby preventing opening of a furthercompartment.

4. In a filing cabinet containing a set of sliding compartments'andincluding hingedly mounted doors, one for each compartment, apparatusfor maintaining the remaining doors of said cabinet in a closed positionwhen a selected one of said doors is opened comprising a slidablelocking bar spanning said compartments, a plurality of fall supportsattached one each to each of said doors, each of said fall supportsbeing provided with a camming surface for momentarily camming saidlocking bar vertically upward when any one of said doors is opened,means on each of said fall supports cooperating with said filing cabinetfor maintaining said door in a horizontal open position, and means forpreventing vertical movement of said locking bar after any one of saidcompartment doors is opened thereby preventing passage of any furtherfall support camming surface past said locking bar to maintain theremaining compartment doors closed.

5. The filing cabinet as set out in claim 4, and further including alocking mechanism for maintaining said slidable locking bar immovablewhen said locking mechanism is in a locked position and permittingmovement of said slidable locking bar when said locking mechanism is inan unlocked position.

6. In a filing cabinet containing a set of slidable compartments andincluding hingedly mounted doors, one for each compartment, apparatusfor maintaining the remaining doors of said cabinet in a closed positionwhen a selected one of said doors is opened comprising a slidablelocking bar spanning said compartments and including a plurality ofnotches therein, a plurality of fall supports attached one each to eachof said doors and each adapted to pass within one of said notches, eachof said fall supports being provided with a camming surface formomentarily camming said locking bar vertically upward when any one ofsaid doors is opened, means on each of said fall supports cooperatingwith said filing cabinet for maintaining said door in a horizontal openposition, and means for preventing vertical movement of said locking barafter any one of said compartment doors is opened thereby preventingpassage of any further fall support camming surface through said notchesto maintain the remaining compartment doors closed.

7. In a filing cabinet containing a set of slidable compartments andincluding hingedly mounted doors, one for each compartment, apparatusfor maintaining the remaining doors of said cabinet in a closed positionwhen a selected one of said doors is opened comprising a slidablelocking bar spanning said compartments, a plurality of fall supportsattached one each to each of said doors, means for momentarily cammingsaid locking bar vertically upward when any one of said doors is opened,means one each of said fall supports cooperating with said filingcabinet for maintaining said door in a horizontal open position, andmeans for preventing vertical movement of said locking bar after any oneof said compartment doors is opened to maintain the remainingcompartment doors closed.

8. In a filing cabinet containing a set of slidable compartments andincluding hingedly mounted doors, one for each compartment, apparatusfor maintaining the remaining doors of said cabinet in a closed positionwhen a selected one of said doors is opened comprising a slidablelocking bar spanning said compartments and including a plurality ofnotches therein, a plurality of fall supports attached one each to eachof said doors and each adapted to pass within one of said notches, meansfor momentarily raising said locking bar vertically upward when any oneof said doors is opened, means on each of said fall supports cooperatingwith said filing cabinet for maintaining said door in a horizontal openposition, a combined friction catch-interlock positioned adjacent eachof said fall supports, means for maintaining said frictioncatch-interlock in a disengaged position when any one of said doors ismoved from an open to a closed position and permitting each of saidfriction catch-interlock to move to a locking position ports, wherebywhen any one of said friction catch-interlock underlays one of said fallsupports as the result of the opening of its respective door theslidable locking bar is prevented from movement thereby preventing thefirst camming surface on any of said closed doors fall supports fromcamming said locking bar upwardly, the effect being that said thenimmovable locking bar acts to prevent the passage of any camming surfaceto maintain the respective door in a closed locked position.

9. In a filing cabinet containing a set of slidable compartments andincluding hingedly mounted doors, one for each compartment, apparatusfor maintaining the remaining doors of said cabinet in a closed positionwhen a selected one of said doors is opened comprising a slidablelocking bar spanning said compartments including a plurality of notchestherein, a plurality of fall supports attached one each to each of saiddoors and each adapted to pass within one of said notches, each of saidfall supports being provided with a first camming surface formomentarily camming said locking bar to an upper position when any oneof said doors is opened, means on each of said fall supports cooperatingwith said filing cabinet for maintaining said door in a horizontal openposition, a combined friction catch-interlock positioned adjacent eachof said fall supports, said fall supports each being provided with asecond camming surface for camming and maintaining said frictioncatchinterlock in a disengaged position when any one of said doors ismoved from an open to a closed position and permitting each of saidfriction catch-interlock to move to a locking position underlying anyone of said fall supports when any one of said doors is moved from aclosed to an open position, the height of said notches being onlysufficient to receive a fall support and a friction catch-interlock whenunderlying one of said fall supports, whereby when any one of saidfriction catch-interlock underlays one of said fall supports as theresult of the opening of its respective door the slidable locking bar isprevented from movement thereby preventing the first camming surface onany of said closed doors fall supports from camming said locking barupwardly, the effect being that said then immovable locking bar acts toprevent the passage of any camming surface to maintain the respectivedoor in a closed locked position.

10. The filing cabinet as set out in claim 9, and further including alocking mechanism for maintaining said slidable locking bar immovablewhen said locking mechanism is in a locked position, and permittingmovement of said slidable locking bar when said locking mechanism is inan unlocked position.

1. In a filing cabinet containing a set of slidable compartments,apparatus for maintaining the remaining compartments of said cabinet ina closed position when a selected one of said compartments is openedcomprising a slidable locking bar spanning said compartments, means formomentarily camming said locking bar vertically to an upper positionwhen any one of said compartments is opened, and means for locking saidslidable locking bar when it has reached its lower position after beingmomentarily cammed upwardly by any one of said compartments being openedthereby preventing opening of a second Compartment.
 2. The filingcabinet as set out in claim 1, and further including a locking mechanismfor maintaining said slidable locking bar immovable when said lockingmechanism is in a locked position, and permitting movement of saidslidable locking bar when said locking mechanism is in an unlockedposition.
 3. In a filing cabinet containing a set of slidablecompartments, apparatus for maintaining the remaining compartments ofsaid cabinet in a closed position when a selected one of saidcompartments is opened comprising a slidable locking bar spanning saidcompartments, means for vertically raising said locking bar to an upperposition when any one of said compartments is opened, means cooperatingwith each of said compartments permitting opening of a compartment whensaid slidable locking bar is in its vertically raised position, andmeans for locking said slidable locking bar in a lower position when anyone of said compartments is opened thereby preventing opening of afurther compartment.
 4. In a filing cabinet containing a set of slidingcompartments and including hingedly mounted doors, one for eachcompartment, apparatus for maintaining the remaining doors of saidcabinet in a closed position when a selected one of said doors is openedcomprising a slidable locking bar spanning said compartments, aplurality of fall supports attached one each to each of said doors, eachof said fall supports being provided with a camming surface formomentarily camming said locking bar vertically upward when any one ofsaid doors is opened, means on each of said fall supports cooperatingwith said filing cabinet for maintaining said door in a horizontal openposition, and means for preventing vertical movement of said locking barafter any one of said compartment doors is opened thereby preventingpassage of any further fall support camming surface past said lockingbar to maintain the remaining compartment doors closed.
 5. The filingcabinet as set out in claim 4, and further including a locking mechanismfor maintaining said slidable locking bar immovable when said lockingmechanism is in a locked position and permitting movement of saidslidable locking bar when said locking mechanism is in an unlockedposition.
 6. In a filing cabinet containing a set of slidablecompartments and including hingedly mounted doors, one for eachcompartment, apparatus for maintaining the remaining doors of saidcabinet in a closed position when a selected one of said doors is openedcomprising a slidable locking bar spanning said compartments andincluding a plurality of notches therein, a plurality of fall supportsattached one each to each of said doors and each adapted to pass withinone of said notches, each of said fall supports being provided with acamming surface for momentarily camming said locking bar verticallyupward when any one of said doors is opened, means on each of said fallsupports cooperating with said filing cabinet for maintaining said doorin a horizontal open position, and means for preventing verticalmovement of said locking bar after any one of said compartment doors isopened thereby preventing passage of any further fall support cammingsurface through said notches to maintain the remaining compartment doorsclosed.
 7. In a filing cabinet containing a set of slidable compartmentsand including hingedly mounted doors, one for each compartment,apparatus for maintaining the remaining doors of said cabinet in aclosed position when a selected one of said doors is opened comprising aslidable locking bar spanning said compartments, a plurality of fallsupports attached one each to each of said doors, means for momentarilycamming said locking bar vertically upward when any one of said doors isopened, means one each of said fall supports cooperating with saidfiling cabinet for maintaining said door in a horizontal open position,and means for preventing vertical movement of said locking bar after anyone of said compartment doors is opened to maintain the remainingcompartment doors closed.
 8. In a filing cabinet containing a set ofslidable compartments and including hingedly mounted doors, one for eachcompartment, apparatus for maintaining the remaining doors of saidcabinet in a closed position when a selected one of said doors is openedcomprising a slidable locking bar spanning said compartments andincluding a plurality of notches therein, a plurality of fall supportsattached one each to each of said doors and each adapted to pass withinone of said notches, means for momentarily raising said locking barvertically upward when any one of said doors is opened, means on each ofsaid fall supports cooperating with said filing cabinet for maintainingsaid door in a horizontal open position, a combined frictioncatch-interlock positioned adjacent each of said fall supports, meansfor maintaining said friction catch-interlock in a disengaged positionwhen any one of said doors is moved from an open to a closed positionand permitting each of said friction catch-interlock to move to alocking position underlying any one of said fall supports when any oneof said doors is moved from a closed to an open position, the height ofsaid notches being only sufficient to receive a fall support and afriction catch-interlock when underlying one of said fall supports,whereby when any one of said friction catch-interlock underlays one ofsaid fall supports as the result of the opening of its respective doorthe slidable locking bar is prevented from movement thereby preventingthe first camming surface on any of said closed doors'' fall supportsfrom camming said locking bar upwardly, the effect being that said thenimmovable locking bar acts to prevent the passage of any camming surfaceto maintain the respective door in a closed locked position.
 9. In afiling cabinet containing a set of slidable compartments and includinghingedly mounted doors, one for each compartment, apparatus formaintaining the remaining doors of said cabinet in a closed positionwhen a selected one of said doors is opened comprising a slidablelocking bar spanning said compartments including a plurality of notchestherein, a plurality of fall supports attached one each to each of saiddoors and each adapted to pass within one of said notches, each of saidfall supports being provided with a first camming surface formomentarily camming said locking bar to an upper position when any oneof said doors is opened, means on each of said fall supports cooperatingwith said filing cabinet for maintaining said door in a horizontal openposition, a combined friction catch-interlock positioned adjacent eachof said fall supports, said fall supports each being provided with asecond camming surface for camming and maintaining said frictioncatch-interlock in a disengaged position when any one of said doors ismoved from an open to a closed position and permitting each of saidfriction catch-interlock to move to a locking position underlying anyone of said fall supports when any one of said doors is moved from aclosed to an open position, the height of said notches being onlysufficient to receive a fall support and a friction catch-interlock whenunderlying one of said fall supports, whereby when any one of saidfriction catch-interlock underlays one of said fall supports as theresult of the opening of its respective door the slidable locking bar isprevented from movement thereby preventing the first camming surface onany of said closed doors'' fall supports from camming said locking barupwardly, the effect being that said then immovable locking bar acts toprevent the passage of any camming surface to maintain the respectivedoor in a closed locked position.
 10. The filing cabinet as set out inclaim 9, and further including a locking mechanism for maintaining saidslidable locking bar immovable when said locking mechanism is in alocked position, and permitting movement of said slidable locking barwhen said locking mechanism is in an unlockeD position.